New MacOS X malware surfaces

HellRTS sets up remote access to infected Macs.

Apple Mac users are being warned to keep a close eye on their systems following the discovery of a new piece of malware for MacOS X.

Dubbed "HellRTS," the malicious tool has been spotted as a proof of concept sample. Thus far no active exploits or attacks have been spotted, though experts warn that samples of the malware have been widely circulating online.

According to MacOS X security specialist Intego, the malware can be spread either through a trojan download or a web-based exploit. Upon installation, the software renames itself after common files and applications as well as adding a copy of itself to the user's start-up folder.

Once infected, the tool allows an attacker to remotely access infected machines as well as remotely install applications and use the infected machines to send emails without user notification.

Intego said that the HellRTS malware is actually a modified version of a malicious application that first appeared for the MacOS in 2004. Because the payload is written as a universal binary, both Intel and older PowerPC systems can be infected.

While still far less common than Windows-based malware, malicious code targeting MacOS X systems has become more prevalent in recent years.

Experts are increasingly warning Mac users to take basic precautions such as avoiding suspicious email attachments and links, downloading software only from trusted sources and keeping both the operating system and all applications current with the latest patches and updates.